Vibration damper



Aug. 2l, 1945.

F. R. MCFARLAND VIBRATION DAMPER Filed Sept. 5, 1942 INVENTOR. Fore-3 t J?. Mc Farid/1d JMW L 7%56- Attornegsl Patented Aug. 21, 1945 VIBRATION DAMPER Forest R. McFarland, Huntington Woods, Mich.,

assignor to Packard Motor Car Company, Detroit, Mich., a corporation of Michigan Application September 5, 1942, Serial No. 457,408

' (ci. 'i4-574) 1 Claim.

This invention relates to vibration dempers for shafts such as are used on internal combustion engines and more particularly on the crankshafts of such engines. It is of the type in which an inertia member is so connected with the shaft that it may move relatively thereto and, by reason of such connection, it `will absorb energy and tend to damp torsional vibrations of the shaft.

One of the objects of the invention is to provide a damper of this character which is simple and inexpensive to construct and which may be readily assembled and disassembled.

Another object of the invention is to separate the rubber damping means and the surface friction damping means of a damper of the charactor above referred to so that in the construe` the following description taken in connection with the drawing, which forms a part of this spacincation, and in which:

Fig. 1 is a face view of a damper incorporating the invention, portions being broken away to show the various elements; and

Fig. 2 is a sectional View of the damper taken on line r-i of Fig. l.

Referring to the drawing, a shaft such as an engine crankshaft is indicated at il! and mounted thereon is a hub member H keyed thereto by a key it and secured thereon as by a nut i3.

The hub member il is formed with two separated disk portions I4 and l5. the disk portion is being shown as detachable from. the hub meme ber, the several screws IB securing the disk 'ib to the hub member and being removable to detach the disk I5 therefrom.

In the assembled form of the damper shown in Fig. 2 an inertia member il shown in the form of a ring or flywheel is arranged between the disk members i4 and I5 of the hub member and the periphery of the disk member i5 is bent over to enclose the inertie member I1 thus forming an. annular ange I8 somewhat separated from the periphery of the inertia member il. As shown the ring or inertia member Il is mounted for rotative movement on the hub member I I with a. bushing 20 between the two members for the purpose of centering the one on the other.

Preferably before the disk member I5 is assembled on the hub member and preferably before any of the other parts are assembled on the inertia member, thedisk member I5 and inertia member I1 are connected together by a rubber means I9, the rubber being bonded to the adjacent surfaces of both members. This rubber means so interconnects the members I5 and il that they may be moved` relatively only by distorting the rubber means. Thus upon torsional vibration of the crankshaft there will be slight relative movement between the inertia member and the shaft which will result in the deformation of the rubberv means i9 and the consequent production of heat therein from internal friction, and thus thev energy of wbration of the crankshaft will be absorbed and dissipated.

The damper also inciudes additional energy absorbing means in the form of surface friction means between the inertia member il and the disk portion it of the hub. This is for the purpose of taking care of certain vibration frequencies of the crankshaft in which the rubber means is not sumcient to dissipate the energy of vibration. l

in the form of the invention shown there is a thin flexible disk it secured to the side of the inertia member il opposite the rubber connection of the inertia member with the disk member it, this being secured to the inertia member by the bolts En Between the disk 25 and the disk member ifi of the vhub ii is a friction ring 2i', which may be formed of cork, asbestos, or similar material, and between the disk 25 and the adjacent surface of the inertia member i l is a backn ing ring it. Seated in recesses 3@ in the inertia member are coiled springs 29 which engage against the backing ring 28' and thereby exert pressure on the disk 2t and the friction ring 2i so that the latter presses frictionally against the inner surface of the disk member it. Thus when there is relative rotative movement of the nertia member and the shaft the friction ring El' will absorb inertia and thereby assist in the damping operation.

For the purpose of protecting the friction means fromA dirt, moisture, oil, etc., two sealing rings are provided, first, the sealing ring 32 arranged in ai! groove 33 formed on the periphery of the disk member it of the hub. Surrounding and holding in place this sealing ring 32 is a metal ring it secured to the adjacent face of the inertia member Il. It may be secured as v,shown by the same bolts 26 that secure the disk purpose of receiving the backing ring 28 above referred to.l

At the end of theshaft a gear is shown secured in place on the hub by the bolts 4I, thus adding an additional securing means for the detachable disk member.

It will be noted .that with the above described construction the inertia member l1 and the disk member I 5 may rst be joined by the bonded rubber construction and then the friction means may be connected to the inertia member. all of this assembling being done before the parts are placed on the shaft. 'Ihen with the two sealing rings 32 and 36 in place the assembled inertia member and disk I5 may be placed on the hub and 4secured thereon by the screws I6. The thickness of the rubber means and the strength of the friction' means against the disk u, the rubber performing the dual function of pressing the friction parts together and of forming one ofthe 'damping elements of the device.

a member fixed to the hub in spaced relation to the disk, an'iner'tia ring intermediate the disk and the member, rubber means between and bonded to the member and the inertia ring, a friction ring between thel disk and the inertia ring, a friction disk fixed to the inertia ring and bearing against the friction ring, a backing ring engaging the friction disk on the face opposite the friction ring engaging portion, and spring springs 29 will determine the pressure of the means seated in the inertia ring and acting against said backing ring and friction .disk to hold the friction ring engaged with the friction disk.

FOREST R.. McFARLAND. 

